The number of people living over the age of 100 has reached a record high, figures show.

In 2012 there were 13,350 centenarians living in the UK, the Office for National Statistics (ONS) said.

Over the last decade alone the number of people who live to 100 has increased by 73%.

During the last 30 years there has been a five-fold increase in the number of people who reach the milestone birthday, according to the ONS report Estimates of the Very Old.

In 2012, 660 people were estimated to be at least 105 years old - another record.

This means that the Queen will be spending more and more time writing birthday cards to centenarians.

At present, she sends a personal congratulatory message to anyone in the United Kingdom celebrating their 100th birthday, their 105th birthday and each year following their 105th birthday.

She can also send birthday messages to centenarians living in countries where she is the head of state.

A Buckingham Palace spokesman said that in 2013 the Queen sent 10,975 messages to people celebrating their 100th birthdays, 486 messages to people celebrating their 105th birthdays and 454 messages to people celebrating their 106th or above birthdays.

She also sends celebratory messages to couples celebrating milestone wedding anniversaries. The tradition of sending messages started during the reign of the Queen's grandfather, George V.

The ONS report states that there were more than half a million people over the age of 90 in the UK in 2012.

For every 100 men aged 90 and over there were 264 women.

While there is a stark contrast between the number of "very old" men and women, the gap between the sexes has tightened - in 2002 there were 336 women aged 90 and over for every 100 men.

Another report from the official statistical body states that life expectancy at birth has increased by two and a half years per decade since 1980 for men and two years per decade for females.

However, UK women are still expected to live for longer than men.

But a third ONS report on healthy life expectancy suggests that even though people are living longer, they are not enjoying all of their years in good health.

Healthy life expectancy estimates the average lifespan spent in very good or good health based on a self-assessment taken from the Census.

The report suggests that baby girls born in 2010-12 can expect to live for 83 years, but just 64.8 of those years will be spent in good health.

Meanwhile, baby boys can expect to live for 79.2 years and feel healthy for 63.5 years, the report suggests.

The report found major regional differences between healthy life expectancies.

In Guildford and Waverley baby girls and boys could expect to live 71.3 and 70.3 years in good health respectively.

But in Bradford a healthy life expectancy for a man is just 52.5 years and 51.6 years for women.